Urban ares throughout the world continue to experience growth and a corresponding increase in vehicular traffic. The demand for office, commercial and residential space in urban areas often makes it economically impractical to maintain at-grade vehicular parking lots. In particular, owners of real estate often can make substantially more profit by developing their land with an appropriate building than they can by using the land as a parking lot. The construction of a building on the site of a former parking lot depletes the supply of at-grade parking spaces, and simultaneously increases the demand for such spaces in proportion to the traffic generated by the new building. Multilevel vehicular parking garages exist in most urban areas. However, structures of this type are expensive to build and operate.
Parking problems also exist for new or used car dealers and for operators of vehicular fleets. These businesses must have a parking capacity to meet their inventory or fleet needs. The costs associated with maintaining a large at-grade parking facility or a multi-level parking garage often will significantly erode the profits of such businesses.
Double-decked parking apparatuses have been available in the prior art. In particular, the prior art parking apparatus includes a platform onto which a vehicle may be driven. The apparatus further includes means for lifting the platform with the vehicle thereon a sufficient distance to enable a second car to be driven under the platform. Thus, the prior art parking apparatus enables two vehicles to be parked in an area approximately the size of a single parking space, and thereby approximately doubles the usage and efficiency of a parking area.
One very effective prior art parking apparatus is shown in U.S. Pat. No. 4,209,276 which issued to the inventor herein on June 24, 1980. The apparatus shown in U.S. Pat. No. 4,209,276 includes a generally horizontal platform that is disposed between a pair of upstanding stanchions. The platform can be selectively raised or lowered relative to the stanchions. The parking apparatus shown in U.S. Pat. No. 4,209,276 includes a pair of cylinders extending upwardly from the top of the stanchions, and pistons extending from the cylinders into engagement with the platform. The pistons are extended from the cylinders to lower the platform and are retracted into the cylinders to raise the platform. Although the parking apparatus of U.S. Pat. No. 4,209,276 is extremely effective, the apparatus defines a height substantially equal to the height of the stanchions plus the height of the cylinders. This overall height typically is 11 feet 4 inches and invariably is higher than the roof of a vehicle disposed on the elevated platform. The overall height of the apparatus shown in U.S. Pat. No. 4,209,276 often prevents using the apparatus in indoor parking facilities.
U.S. Pat. No. 4,772,172 also issued to the inventor herein and shows an improvement to the inventor's earlier U.S. Pat. No. 4,209,276. The apparatus shown in U.S. Pat. No. 4,772,172 includes a parking platform that is disposed between a pair of substantially vertical stanchions and that can be raised and lowered relative to those stanchions. Stabilizer bar assemblies are provided on each side of the parking platform. Each stabilizer bar assembly includes a rocker arm pivotably connected to the platform and a control arm pivotably connected to a base. The rocker arm and the control arm are further pivotably connected to one another. Thus, the stabilizer bar assembly effectively folds upon itself as the parking platform is lowered and expands as the parking platform is raised. A piston and cylinder assembly is pivotably connected to each stanchion and to the rocker arm. Movement of the piston in one direction causes the rocker arm to fold toward the control arm and thereby lowers the parking platform. Movement of the piston in the opposed direction causes the rocker arm to rotate away from the control arm, and elevates the parking platform. The apparatus shown in U.S. Pat. No. 4,772,172 achieves the desirable objective of combining the lifting and stabilizing functions of the parking apparatus, thereby substantially improving &:he stabilization of the apparatus. In this regard, it must be emphasized that stability is an extremely important requirement for a parking apparatus, since the apparatus must efficiently raise and lower a vehicle and steadily hold the vehicle in an elevated condition for hours on end. Furthermore, the weight and center of gravity of vehicles vary considerably, thereby making stability of the apparatus even more important. The maximum height of the apparatus shown in U.S. Pat. No. 4,772,172 generally will be defined by the roof of the vehicle parked on the platform, and typically will be between 9.5 and 10.0 feet. This is a significant improvement over the apparatus in U.S. Pat. No. 4,209,276 which defined a total height of 11 feet 4 inches. In view of this difference, the parking apparatus of U.S. Pat. No. 4,772,172 can be used in many indoor locations that were not available to its predecessor, as well as all outdoor parking lots.
The disclosures of U.S. Pat. No. 4,209,276 and U.S. Pat. No. 4,772,172 are incorporated herein by reference.
The above described prior art vehicular parking apparatus has achieved significant commercial acceptance and is available in urban areas throughout the world. However, even further parking efficiencies would be desirable. In this regard, a tri-level parking apparatus could offer such further efficiencies in the use of the limited land available for vehicular parking. More particularly, a tri-level parking apparatus could mean a fifty percent increase in revenues to the operator of a parking facility as compared to the above described prior art double-decked parking apparatus. Similarly, a tri-level parking apparatus can yield much more efficient use of space to car dealers and owners of vehicular fleets. However, stability becomes an even more important design consideration for tri-level parking apparatus.
One prior art tri-level parking apparatus is shown in U.S. Pat. No. 4,674,938 which issued to Van Stokes et al. on June 23, 1987. The apparatus, shown in U.S. Pat. No. 4,674,938 includes a large cumbersome frame having a complex arrangement of pulleys and straps that are intended to maintain stability as they lift the platforms from their lower positions to their respective elevated positions. In operation, upper and lower parking platforms shown in U.S. Pat. No. 4,674,938 are disposed in their respective lowermost positions and a vehicle is driven onto the upper platform. The upper platform is then lifted to a first elevated position which enables a vehicle to be driven onto the lower platform. The upper platform is raised again to a second elevated position. A strap extending between the upper and lower platforms causes the lower platform to be raised into the first elevated position as the upper platform is raised into the second elevated position. Thus, the movement of the upper platform from the first to the second elevated positions effectively pulls the lower platform upwardly. A third vehicle can then be driven under the lower parking platform. The complex arrangement of pulleys and straps prevents independent movement of the lower platform relative to the upper platform.
In view of the above, it is an object of the subject invention to provide an efficient tri-level vehicular parking apparatus.
It is another object of the subject invention to provide a tri-level vehicular parking apparatus that avoids complex arrangements of pulleys and straps.
It is a further object of the subject invention to provide a tri-level parking apparatus that enables entirely independent operation of the parking platforms thereof.
Still another object of the subject invention is to provide a tri-level parking apparatus that requires only approximately the space previously afforded to a bi-level parking apparatus.
Yet a further object of the subject invention is to provide an extremely stable tri-level parking apparatus.